Well completion apparatus



E. F. COOKE WELL COMPLETION APPARATUS- Oct. 16, 1945.

Filed Oct. 7, 1941 3 Sheets-Sheet l Z [I J E J E J 1' I 8 1 8 I q I.

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WELL COMPLETION APPARATUS Filed Oct, 7, 1941 SSheets-Sheet 2 42 EIHIE I]E 3 E 11113 c Q I 5 M N" E 1 EFT] ET] E J I gnu (1,} 1M3 E 1 7 1 Ar Q mI w x1; llk 2% I 6 m I g *2? 4 2 7 1 A. M

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WELL COMPLETION APPARATUS Filed Oct. .7, 19-41 1 3 Sheets-Sheet 3Patented Got. 16, 1945 WELL COMPLETION APPARATUS Edward F. Cooke,Beaumont, Tex., assignor' to Beaumont Iron Works Company, Beaumont,Tex., a corporation of Texas Application October 7, 1941, Serial No.4,013

2 Claims.

This invention relates to oil well completion apparatus and has for itsgeneral object the provision of means for sealing the well andwithdrawing or reseating, without the escape of fluid pressure from thewell, the valve cage containing the check valve which is customarilyused to block the bore of the inner pipe string while the latter isbeing set under a mud head or blow-out preventer.

More specific objects will appear as the following description of apreferred and practical embodiment thereof proceeds.

In the drawings which accompany and form a part of the followingspecification and throughout the several figures of which the samereference characters have been employed to designate identical parts: 7

Figure l is a longitudinal sectional View through the valve cage settingand removing tool embodying the principles of the invention;

Figure 2 is a longitudinal section through a casing head and accessoryequipment mounted in relation thereto;

Figures 3 and 4 are complementary views in longitudinal cross-section,showing the casing head with the Christmas tree mounted thereupon andthe valve cage removing tool of the subject invention in operativeposition for removing the valve cage, Figure 3 being a continuation ofthe upper part of Figure 4.

Figure 5 is a longitudinal sectional view of acv blow-out preventer;

Figure 6 is a longitudinal sectional view of the handling joint andhandling nipple in position with respect to the valve cage;

Figure 7 is a cross-section taken along the line 1-? of Figure 6;

Figure 8 is a cross-section taken along the line 88 of Figure 1.

Referring now in detail to the several figures, and first adverting toFigure 2, this shows the upper end of a well casing I, having the casinghead 2 affixed thereto. Said casing head is of conventionalconstruction, having a flanged upper end 3, a downwardly taperedintermediate bore 4, a lower portion 5 of relatively small diameter, andan upper portion 6 of relatively large diameter, the diameters of saidupper and lower portions corresponding to the respective diameters ofthe tapered bore. The casing head has the customary lateral apertures land 8, to one of which an outlet pipe 9 is connected, the other beingconnected to a pipe for admitting or withdrawing fluid from the well.Above the tapered bore the casing head is provided with the threadedapertures l 1, into which the set screws [2 re-, ciprocate, said setscrews being each packed by a gland l3 and having polygonalwrench-engaging outer ends 14!, permitting them to be retracted oradvanced by the use of a wrench. The inner ends of said set screws arepreferably tapered. As will be apparent to those skilled in the art, andas will presently appeanthis casing head is designed to receive a hangerfor supporting the inner pipe string I 5 and for sealing the space abovethe apertures 'l and. 8 and between the inner pipe string and thecasing, against loss of fluid under pressure from the well.

It is assumed that at this stage of its completion, that is to say,before the inner string of pipe or the hanger is in place, the well isfilled with heavy mud pumped in during the drilling operation and theweight of which mud dominates the fluid pressure from within the well.

For the sake of precaution, the accessory assembly l5 shown in Figure 2above the casing head and designated as a whole by the referencecharacter I 6 may have been bolted onto the casing head as shown in Fig.2 during the latter part of the drilling operation as a guard againstthe development of excessive pressure which might overcome the weight ofthe mud. This accessory assembly is conventional and has a number ofuses in connection with the several operations involved in thecompletion of the well, all of which are familiar to those skilled inthe art, and which need not here be reiterated. The accessory assemblycomprises the gate valve H and above it, a pair of spaced blow-outpreventers l8 and I9, which may be alternately operated so as to bringany enlargement on the outside of the inner string of pipes sequentiallypast the lower blow-out preventer by opening the latter while the upperblow-out preventer is closed and then bringing it above the upperblowout preventer and out of the well by first closing the lowerblow-out preventer and then opening the upper blow-out preventer.

In inserting the inner string of pipes into the well, the accessoryassembly I6 will always be in place. It may be desired first to sink ascreen or packer near the bottom of the well. To do this the screen orpacker is attached to the bottom end of the first pipe section and thenpassed through the blow-out preventer, the open gate valve'l l andthrough the casing head and Well casing, other pipe sections being addeduntil the requisite length of inner pipe string is in the well. Thehanger bushing 2 I is screwed onto the upper end of the top .externallythreaded zone pipe section 20. The details of this hanger bushing can beseen in Figure 4, where it will be observed that said bushing isexternally threaded at; the top to receive the hanger 22, which however,at this stage of the proceedings is not put in place. The bushing 2| hasa lower threaded end 23 receiving the upper end of pipe section 20, anintermediate unthreaded cylindrical bore 24 for receiving the lower endof a valve cage 25. The bushing 2| also has an upper bore 26 having along pipe thread considerably longer than sufficient to secure the valvecage 25.

After the hanger bushing 2| has been put in place the valve cage 25 ofthe subject invention is placed in position. This has an intermediate 21having a pipe thread which fits the lower part of the threaded bore 25.It has a lower cylindrical portion 28 adapted to freely fit within thecylindrical bore 24 of the bushing 2|. The valve cage 25 also has anelongated cylindrical portion 30 above its threaded zone and ofconsiderably smaller diameter than the upper bore of the bushing 2| soas to leave room for a handling nipple 29 to be telescoped over theupper part of the valve cage and to screw into the upper part of thethreaded bore 25 and by means of which the inner pipe string may beraised or lowered.

The upper cylindrical portion 30 of the valve cage is of reduceddiameter near the top, forming a beveled shoulder 3| and the upper endof the valve cage is also beveled, as shown at 32. The upper end of thevalve cage is provided with diametrically opposite longitudinal recesses33, which form a coupling element in connection with the valve cageremoving tool which will presently be described. The valve cage has abore extending therethrough, including a restricted intermediate portion34 forming an upwardly beveled valve seat 35 engaged by a check valve 36having a guiding stem 31 passing through a guiding aperture 38 in anapertured disk 39 which is screwed into the lower end of the valve cage.The valve, as shown, is also provided with a guiding spider 4|).

The check valve 36 closes against well pressure within the inner pipestring, so that when the valve cage is in position in the bushing 2| thelower pipe string is sealed against the escape of gas or liquid underpressure from within the inner pipe string. As the valve cage willeventually be removed it is desirable that it shall not screw so tightlywithin the bushing 2| asto make its removal difficult, and with this endin view an annular rubber sleeve 4| is mounted upon the lowercylindrical portion 28 of the valve cage up against the threaded portion21, and as the latter is screwed into the bore 26 of the bushing 2| therubber sleeve is deformed, embossing itself into the threads of the bore25 and forming a fluidtight seal without the necessity of the valve cagebeing screwed excessively tight.

Now, when the bushing 2| and the valve cage 25 have been assembled onthe top end of the pipe section 20 while the latter was above theaccessory assembly IS, a handling nipple 29 is slipped over the upperportion 30 of the valve cage and screwed into the bore 26 of the bushing2|, as shown in Figure 6.

As will be seen, the handling nipple 29 is screwed to the lower end of ahandling joint or pipe section 42 which may be of any length desired tocarry the pipe string as deeply as may be necessary into the well. Inorder to wash the heavy mud from the well, lighter liquid, for example,

water under pressure, will be pumped down through the handling nippleand through the valve cage. The handling nipple, therefore, carries asuitable strainer 53. The water under pressure displaces the valve 36,forcing its way down through the inner pipe string, displacing the mudtherein, finally issuing from the lower end of the screen, displacingthe mud from the annular space between the screen and the well casing orthe open hole, as the case may be, the mud being discharged through asuitable outlet, not shown, in the lower blow-out preventer l8. Afterthis operation, the screen is lowered to bottom and released, the packerset in place and released and the fluid is again caused to flow downwardthrough the inner pipe 20 to wash the mud from within the screen andfrom the annular space between the inner pipe and the screen and/or wellcasing.

The screen usually is equipped with a valve on the lower end whichprevents the fluid in the well bore from rising in the inner pipe, butwhich permits fluid to flow downward and out. This valve is closed inthe act of releasing the screen from the inner pipe. Where a screen isnot used or is not equipped with a valve, a glass or metallic breali-outdisc is inserted in the lower end of the inner pipe, and broken out bydropping a bolt or go-devil through the inner pipe. When this method isused the valve cage is inserted in place in the bushing immediatelyafter releasing the godevil. By the above means the fluid in the wellbore is prevented from flowing up and out the inner pipe before thevalve cage 25 is put in place in bushing 2|.

By manipulating the blow-out preventers, the handling joint may be letdown with the inner pipe string to any desired depth, or elevated to anyextent that may be necessary in order to accomplish the washing of thewell, without the risk of the escape of any fluid under pressure at thetop of the casing head or through the inner pipe string.

The washing of the well now having been completed, it is next desired topermanently hang the pipe string. The inner pipe string is hauled up bythe handling joint until the bushing 2| is again above the accessoryassembly 46, in which position it is temporarily supported and thehandling nipple unscrewed from the bore 26. This is done to permit theintercalation of .the hanger 22. Figure 4 shows that the hanger 22 has alower cylindrical portion 43, the diameter of which is smaller than thatof the casing head in the zone of the apertures I and 8, so that theseapertures will not be occluded when the hanger is in place. Theintermediate portion of the hanger has a taper corresponding to thetapered zone 4 of the casing head and adapted to seat thereupon with theintervention of the packing rings 44. The top of the hanger is inwardlyand upwardlyrtapered, as shown at 45 in Figure 4, this portion of thehanger being in the zone of the set screws |2 when the hanger is inplace and wedgingly engaged by said set screws to hold the hanger to itsseat. The hanger has a through bore 46 of such size to freely pass thehandling nipple and also, as will appear, to pass the tool which isemployed in the removal of the valve cage. It is noted in Figure 2 thatthe continuous bore through the accessory assembly l6, when the blow-outpreventers and gate are open, is of sufliciently large diameter to passa hanger that will fit in the tapered bore 4 of the casing head.

After the hanger has been screwed onto the upper end of the bushing 21,the handling nipple is lowered through said hanger and again screwedinto the threaded bore 26 of the bushing 2|. The lower pipe string,including the hanger, is passed successively through the blowoutpreventers l9 and I8 and through the open gate valve ll until it restsupon its seat 4 in the casing head. The set screws are then advancedwedgingly against the upper portion of the hanger, whereby the annularspace between the inner pipe string and the well casing is sealed offfrom the escape of fluid under pressure by way of the top of the casinghead, and the hanger together with the inner pipe string are securedfrom being forced upwardly due to excessive fluid pressure in the well.The inner pipe string is also permanently suspended at the properdistance in the well. At the same time, the check valve 35 seals theinner pipe string from the escape of fluid under pressure.

Under these circumstances, the handling joint and nipple and theaccessory assembly l6, shown in Figure 2, may be removed and thepermanent conventional Christmas tree installed.

Christmas tree structures, of course, differ, but by way of example theChristmas tree as shown, comprises a gate valve 47, Figure 4, having aflanged base 38 which is bolted to the flange 3 of the casin head. Abovethe gate valve 41 is a cros Q9, having the lateral distribution outlets5i! and 5i and the axial outlet 52. final installation, other members orChristmas tree may be connected to the outlet 52, but in the presentstage of completion of the well an adapter 54 is screwed into the outlet52, providing a flange 55 to receive the base of the valve withdrawingtool. The latter is shown separately in Figure l, and in operativerelation to the well structure in Figures 3 and 4.

Referring to Figure 1, there is a hand wheel support generallydesignated by the reference character 56, consisting of a flange base5?, a tubular body 58 and a bearing receiving socket 51 screwed one toanother and made integral by welding so that they form a substantiallyintegral member. A hand wheel Eli has a shaft 5! with an intermediateintegral collar 62. Said collar rests upon a wear ring 63 retained on aflange at the bottom of the bearing socket 59. An end thrust ballbearing 6 rests upon the top of the collar and is retained by a ring nut65 screwed into the bearing socket. A packing gland t6 surrounds theshaft 65 above the ring nut. The shaft 55 terminates preferably at thepoint 6'! a short distance below the supporting flange, and carries akeyway 63 substantially throughout its length below the collar 62. Theshaft of the hand wheel is rotatable but not reciprocable Within thesupport 53.

A relatively long externally screw-threaded sleeve 69 telescopes overthat portion of the shaft 6! below the bearing socket and screws throughthe flanged base 51. Said sleeve at its upper end carries a key 10,which plays within the keyway 58. Thus, when the hand wheel is rotated,the sleeve 69 reciprocates upwardly or downwardly with respect to thehand wheel support.

At its lower end, the sleeve 69 carries a tubular fitting H, known inthe industry as an overshot. This is preferably screwed to the lower Inthe end of the sleeve 69 and in addition, welded, so

of the bushing 21 through the rotational movement of the sleeve 69 ineither direction. For the purpose of effecting this coupling, theovershot is provided with a transverse pin 12 intersecting its bore andwhich is adapted to enter the .recesses 33 in the valve cage. The boreof the overshot is of two diameters, the lower portionfltting over thepart 30 of the valve cage, and the upper portion fitting over the upperpart of the valve cage of reduced diameter. The bore of the overshot isformed with a tapered shoulder 73 joining the parts of relatively largeand small diameters, and which shoulder fits upon the tapered shoulder31 of the valve cage. A compressible annular sleeve 14 is secured withina suitable seat in the lower portion of the bore of the overshot. In itsnormal position, as shown in Figure l, the internal diameter of thesleeve 14 less than the diameter of the lower part of the bore of theovershot and correspondingly less than the diameter of the portion 30 ofthe valve cage. When the overshot is forced down over the valve cage,the sleeve M is compressed so that it tightly grasps the portion of thevalve cage which it surrounds. The overshot is provided with a pluralityof apertures 15 in the zone or" the sleeve It, providing spaces intowhich the sleeve bulges when compressed thereby preventing the sleevefrom becoming displaced. The entire valve cage removing tool, asillustrated in Figure 1, is of course, designed to be used upon variouswells which many differ in length from the location of the valve cage tothe top of the Christmas tree, and the externally threaded sleeve isconsequently made of a length to suit the longest of these distances.Differences in the distances from valve cage to top of Christmas tree indifferent wells are compensated by selecting adapters 54 of differentand appropriate 7 length.

In order to remove the valve cage 25, the entire tool, as illustrated inFigure l, is placed above and in alignment with the adapter 54, and theovershot. and threaded sleeve 69 inserted through the Christmas tree,the gate valve 41 and into operative proximity to the valve cage 25.Assuming that the proper adapter 54 has been employed, the flanged base51 may now be brought down upon the flange 55 of the adapter and more orless loosely bolted in place. The hand wheel is then turned in adirection to screw the externally threaded sleeve 69 downward.Presently, the bottom end of the overshot H, which is internally taperedas at 16, centers over the tapered end 32 of the valve cage and theovershot freely moves down upon the valve cage until the compressiblesleeve i l abuts against the tapered shoulder 34 of the valve cage. Onecan tell when this contact takes place, by the resistance encountered bythe hand wheel. The bolts between the flanged base 51 of the valve cageremoving tool and the flange 55 of the adapter are then removed and theflanged base 5'! screwed upwardly by hand along the threaded sleeve 69until it is separated from the flange by a, distance somewhat greaterthan the longitudinal distance of the lower end of the compressiblesleeve .14 from the bottom of the pin 12. The flanged base 5? is thenforced downwardly, the handwheel being rotated, if necessary, so as tocause pin 12 to slide within recesses 33 of valve cage 25, carrying withit the threaded sleeve 69 until it will go down no further. Thisindicates that the pin 12 is resting in the bottom of the recesses 33 ofthe valve cage, and that the compressible sleeve 14 has been forced downupon the portion 30 of the valve cage and is tightly gripping the same.The threaded base 51 of the tool is then screwed down into sealingcontact with the packing ring I! which intervenes between the twoflanges. The bolts are then replaced and tightened. The hand wheel 60 isthen turned in a direction to screw the threaded sleev 69 in an upwarddirection. This unscrews the valve cage from the threaded bore 26 of thebushing 2|, and no great effort is required to do this because the valvecage was not screwed tightly into place, in view of the rubber sleeve4|, the function of which has been explained. The threaded sleeve 69 isscrewed upwardly until the valve cage is above the gate valve 41. Thisposition can be ascertained by the ability of the operator to close thegate valve. After the gate valve has been closed the bolts which securethe valve removing tool to the adapter 54 are removed and the tool ispulled out longitudinally, bringing with it the valve cage which isgripped by the compressible sleeve 14. It is obviously not necessary toemploy blow-out preventers inremoving the valve cage. After the valveremoving tool has been removed the adapter 54 may be taken off and thesuperposed members of the Christmas tree connected to the outlet opening52. The gate valve 41 may then be' opened.

In Figure 5 a modified form of blow-out preventer is shown which is partof the accessory assembly 18 and is, in fact, not apart of the subjectinvention, but introduced merely to show how the hanger 22 is insertedwithin the chamber 19 between the blow-out preventers where this type ofblow-out preventer is used, the blowout preventer comprising a flexiblerubber bushing 88 having a skirt portion 8| which automatically gripsthe inner pipe string including the handling joint 42, and whichautomatically spreads to pass the couplings in the pipe string,including the bushing 2|. This blow-out preventer is retained by a ringnut 82 and it is necessary to remove the blow-out preventer in order toinsert the hanger 22. The procedure is as follows. The innerpipe'string, including the bushing 2| and the landing joint and nipple,butwithout the hanger 22, is lowered through the blow-out preventer 80until it is within the chamber 79, the lower blow-out preventer l8 beingclosed against the pipe section 20. The ring nut 82 is then removed andthe pipe string raised. This causes the handling nipple 29 or thebushing 2| to push against the skirt 8| of the blowout preventer,lifting the blow-out preventer out of its seat in the casing 83. Thepipe string is then suitably supported, the handling joint and nippleunscrewed from the bushing 2|, the hanger 22 screwed on the bushing 2|,the blowout preventer pushed up over the handling nipple and onto thehandling joint 42. The handling joint and nipple are then passed throughthe hanger and secured in the threaded bore 26 of the bushing 2|, thepipe string then lowered until the hanger is in the chamber 19, theblowout preventer replaced on its seat within the casing 83 and the ringnut 82 screwed back into place. The pipe string with the hanger may thenbe let down through the lower blow-out preventer and lodged upon itsseat in the casing head.

It is obvious that reversal of the proceeding operations allows placingthe valve cage 25 within the bore 25 of bushing 2| to restrict or stopthe flow of fluid with the inner pipe to allow replacing portions of theChristmas tree or to reinstall the assembly IE to all further work onthe well bore.

While I have in the above description disclosed what I believe to be apreferred and practical embodiment of the invention, it will beunderstood to those skilled in the art that the specific details ofconstruction and the arrangement of parts are by way of illustration andnot to be construed as limiting the scope of the invention which isdefined in the appended claims.

What I claim as my invention is:

1. Well completion apparatus comprising a rotary and reciprocatory valvecage withdrawing means comprising a base, a shaft carried by the baseand rotatably mounted with respect thereto, means for manually rotatingsaid shaft, a sleeve coaxial with said shaft and in telescopic relationthereto, screwing through said base and extending therebeyond, alongitudinal sliding connection between said shaft and sleeve wherebyupon rotation of said shaft said sleeve simultaneously rotates andreciprocates by virtue of the screw connection between said sleeve andbase, and a tubular overshot secured coaxially to the remote end of saidsleeve, said overshot having a transverse pin in the upper part of itsbore adapted to couple positively with complementary coupling means on ascrew seated valve cage upon which said overshot is adapted totelescope, for unseating said valve cage, and having a compressiblesleeve in the lower part of its bore adapted to be expanded by saidvalve cage into gripping relation thereto when said overshot is forciblytelescoped over said valve cage.

2. In well completion apparatus, a Valve cage remover comprising a handwheel unit including a base adapted to be bolted to the well headstructure and form a seal for the well, a shaft journaled in the baserotated by said hand wheel, a screw shaft threaded through a socket insaid base and having a spline connection with said hand wheel shaft tosimultaneously rotate and reciprocate responsive to actuation of saidhand wheel, said screw shaft terminating in a tubular portion having acompressible gripping ring retained in its lower end and a transversepin above said ring.

EDWARD F. COOKE

